where does my daughter/granddaughter declare their €3K gift or do they have to.
Also can I gift €3K to my other daughter who lives and pays taxes in France. She has a house in Ireland and receives rental income and pays tax on it in Ireland.
The 3k small gift exemption is an Irish treatment. If your daughter is tax resident in France, it's French tax rules that apply, and they are different.
Here's a case study which explains the French system: